A high-precision gas metering device

Abstract

The utility model belongs to fluid metering technical field discloses a kind of high-precision gas metering device, including meter body, air inlet and gas outlet and metering core body and main control circuit board, metering core body includes ultrasonic transducer, rectifier steady flow component and temperature sensing component, rectifier steady flow component includes at least one layer honeycomb rectifier and one layer porous plate, honeycomb rectifier is located upstream, and porous plate is located downstream, temperature sensing component includes two temperature sensors, two temperature sensors are respectively installed in the upstream and downstream of rectifier steady flow component;Main control circuit board is electrically connected with a pair of ultrasonic transducer and two temperature sensors.The utility model is by the multistage rectification structure of honeycomb rectifier and porous plate, venturi flow channel optimization and ultrasonic transducer tilt installation design, can significantly reduce flow field disturbance, while it can solve the problem that traditional ultrasonic gas meter is sensitive to flow velocity distribution, to improve the measurement accuracy in full flow range.

Description

Technical Field

[0001] This utility model relates to the field of fluid metering technology, and in particular to a high-precision gas metering device. Background Technology

[0002] Gas meters are indispensable metering devices in urban gas supply systems. Their accuracy directly affects the fairness of trade settlement and the economic benefits of gas supply companies. Currently, the gas meters widely used by residential and industrial users are mainly diaphragm gas meters and ultrasonic gas meters.

[0003] Diaphragm gas meters are technologically mature and have low costs, but they contain mechanical moving parts (such as diaphragms, connecting rods, and slide valves). After long-term operation, mechanical wear can easily lead to a decrease in metering accuracy. Furthermore, under low-flow and small-flow conditions, the metering sensitivity and accuracy are often insufficient due to mechanical inertia and sealing issues.

[0004] Ultrasonic gas meters, as a novel type of instrument, calculate flow velocity and flow rate by measuring the time difference of ultrasonic wave propagation in a fluid along and against the flow. They have no moving mechanical parts and a small starting flow rate. However, existing ultrasonic gas meters still have the following problems: 1) High flow field sensitivity: When gas flows through the meter body, if the flow field is unstable (e.g., eddies or uneven velocity distribution), it will seriously affect the propagation of the ultrasonic signal and the measurement of flight time, leading to measurement errors; 2) Imperfect temperature compensation: The volume and sound velocity of gas are significantly affected by temperature. Existing instruments mostly use a single temperature sensor for compensation, which is difficult to reflect the real-time and average temperature of the gas inside the meter body. Especially when there are sudden changes in flow rate or ambient temperature, the compensation accuracy is limited. Therefore, we propose a high-precision gas metering device. Utility Model Content

[0005] To address the technical problems described in the background section, this utility model provides the following technical solution: A high-precision gas metering device includes a meter body, an inlet and an outlet installed at both ends of the meter body and connected to each other, a metering core and a main control circuit board installed on the meter body. The metering core includes a pair of ultrasonic transducers for measuring gas flow rate, a rectifier and flow stabilizer assembly, and a temperature sensing assembly. The rectifier and flow stabilizer assembly is installed in the metering flow channel between the inlet and the ultrasonic transducers. The rectifier and flow stabilizer assembly includes at least one layer of honeycomb rectifier and one layer of perforated plate. The honeycomb rectifier is located upstream and the perforated plate is located downstream. The temperature sensing assembly includes two temperature sensors, which are respectively installed upstream and downstream of the rectifier and flow stabilizer assembly. The main control circuit board is electrically connected to a pair of ultrasonic transducers and two temperature sensors, and the main control circuit board is configured to calculate the gas flow rate based on the signals from the ultrasonic transducers and the average temperature values ​​from the two temperature sensors.

[0006] As a technical solution of the high-precision gas metering device of this utility model, the meter body is provided with an inwardly protruding reinforcing wall at the installation position corresponding to the ultrasonic transducer.

[0007] As a technical solution of the high-precision gas metering device of this utility model, the gas outlet is provided with a venturi-structured narrowing section, and a gradually expanding section is connected downstream of the narrowing section.

[0008] As a technical solution of the high-precision gas metering device of this utility model, the pair of ultrasonic transducers are installed at an angle relative to each other, so that the ultrasonic signal propagation path and the gas flow direction form an acute angle.

[0009] As a technical solution of the high-precision gas metering device of this utility model, the ratio of the honeycomb pore diameter of the honeycomb rectifier to the pore diameter of the porous plate is 2:1 to 5:1, and the opening rate of the porous plate is 40% to 60%.

[0010] As a technical solution of the high-precision gas metering device of this utility model, the two temperature sensors are respectively embedded in the inner wall of the meter body, and the sensing end of the temperature sensor is exposed in the metering flow channel.

[0011] As a technical solution of the high-precision gas metering device of this utility model, the main control circuit board integrates a signal conditioning module for amplifying, filtering and digitally processing ultrasonic signals.

[0012] Compared with the prior art, the present invention has at least the following beneficial effects: 1. This utility model, through a multi-stage rectification structure consisting of a honeycomb rectifier and a perforated plate, optimization of the Venturi flow channel, and tilted installation design of the ultrasonic transducer, can significantly reduce flow field disturbance and solve the problem of traditional ultrasonic gas meters being sensitive to flow velocity distribution, thereby improving the metering accuracy across the entire flow range.

[0013] 2. This utility model, by combining dual temperature sensors with an average temperature algorithm, can reflect the overall temperature change of the gas in real time, thereby overcoming the limitations of local temperature measurement by a single sensor. At the same time, it enhances the compensation capability for changes in sound velocity and volume, especially reducing temperature drift error when there are sudden changes in flow rate.

[0014] 3. This utility model improves mechanical stability through reinforced wall design, reduces environmental interference through embedded sensor layout, and ensures signal processing efficiency through integrated signal conditioning module, thereby comprehensively improving the long-term reliability and adaptability of the device to complex working conditions. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Among them: Figure 1 This is a schematic diagram of the main structure of this utility model.

[0016] Figure 2 This is a cross-sectional structural diagram of the present invention.

[0017] Figure 3 For the present utility model Figure 2 Enlarged structural diagram at point A in the middle.

[0018] Explanation of reference numerals in the attached figures: In the diagram: 1. Body; 2. Air inlet; 3. Air outlet; 301. Reduction section; 302. Expanding section; 401. Ultrasonic transducer; 402. Temperature sensor; 501. Honeycomb rectifier; 502. Perforated plate; 6. Reinforcing wall; 7. Main control circuit board; 701. Signal conditioning module. Detailed Implementation

[0019] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0020] Reference Figures 1-3 A high-precision gas metering device is provided, comprising a meter body 1, an inlet 2 and an outlet 3 installed at both ends of the meter body 1 and connected to each other, a metering core and a main control circuit board 7 installed on the meter body 1, wherein the microprocessor on the main control circuit board 7 calculates the flow rate based on the time difference method, using the following formula: , where (L) is the sound path, (θ) is the included angle, and (t) is the propagation time; The metering core includes a pair of ultrasonic transducers 401 for measuring gas flow rate, a rectifier and flow stabilizer assembly, and a temperature sensing assembly. The rectifier and flow stabilizer assembly is installed in the metering channel between the air inlet 2 and the ultrasonic transducers 401. The rectifier and flow stabilizer assembly includes at least one layer of honeycomb rectifier 501 and one layer of perforated plate 502. The honeycomb rectifier 501 is located upstream, and the perforated plate 502 is located downstream. The temperature sensing component includes two temperature sensors 402, which are installed upstream and downstream of the rectifier and stabilizer component, respectively. The data from the two temperature sensors 402 are taken as the arithmetic mean and corrected for the gas velocity (c=331.5+0.6T) (T is the average temperature). The main control circuit board 7 is electrically connected to a pair of ultrasonic transducers 401 and two temperature sensors 402. The main control circuit board 7 is configured to calculate the gas flow rate based on the signal from the ultrasonic transducers 401 and the average temperature value from the two temperature sensors 402. In application, the combination of the honeycomb rectifier 501 and the perforated plate 502 stabilizes the gas flow field in layers, reduces turbulence and uneven velocity distribution, and improves the accuracy of ultrasonic measurement. At the same time, the dual temperature sensors 402 monitor the gas temperature before and after rectification, and take the average value to compensate for changes in sound velocity and volume, reducing the impact of sudden temperature changes or local temperature differences on measurement.

[0021] Reference Figure 2 and Figure 3 The meter body 1 has an inwardly protruding reinforcing wall 6 at the installation position corresponding to the ultrasonic transducer 401. In application, the reinforcing wall 6 design enhances the structural rigidity of the meter body 1, reduces vibration interference at the installation position of the ultrasonic transducer 401, ensures the stability of the signal propagation path, and avoids measurement errors caused by mechanical deformation.

[0022] Reference Figure 1 and Figure 2 The outlet 3 is provided with a venturi-structured narrowing section 301, and a gradually expanding section 302 is connected downstream of the narrowing section 301. In application, the venturi narrowing section 301 and the gradually expanding section 302 optimize the flow velocity distribution at the outlet 3. Through the fluid control of the gradually narrowing acceleration and gradually expanding deceleration, the generation of downstream eddies is suppressed, and the influence of flow field disturbance on the metering is further reduced.

[0023] Reference Figure 2 and Figure 3 A pair of ultrasonic transducers 401 are installed at an angle relative to each other, so that the ultrasonic signal propagation path forms an acute angle with the gas flow direction. In application, the tilted ultrasonic transducers 401 extend the propagation path of ultrasonic waves in the gas, increase the sensitivity of the forward and reverse flow time difference signal, and especially improve the measurement accuracy under low flow rate conditions.

[0024] Reference Figure 2 and Figure 3The ratio of the honeycomb aperture of the honeycomb rectifier 501 to the aperture of the perforated plate 502 is 2:1 to 5:1, and the opening ratio of the perforated plate 502 is 40% to 60%. In application, the control of the ratio of the honeycomb aperture to the aperture of the perforated plate 502 (2:1 to 5:1) and the optimization of the opening ratio of the perforated plate 502 (40%-60%) can balance the flow field stability and pressure loss, and avoid the increase of gas resistance due to excessive rectification.

[0025] Reference Figure 2 and Figure 3 Two temperature sensors 402 are embedded in the inner wall of the meter body 1, and the sensing end of the temperature sensor 402 is exposed in the metering flow channel. In application, the embedded design of the temperature sensor 402 is directly exposed in the flow channel to sense the real temperature of the gas in real time, avoid measurement deviation caused by the thermal conduction lag of the meter body 1 material, and improve the temperature compensation response speed.

[0026] Reference Figures 1-3 The main control circuit board 7 integrates a signal conditioning module 701 for amplifying, filtering and digitally processing ultrasonic signals. The signal conditioning module 701 includes a preamplifier (60dB gain), a bandpass filter (1MHz center frequency), and an ADC sampling module (16-bit resolution). In application, the integrated signal conditioning module 701 amplifies, filters and digitizes ultrasonic signals to eliminate environmental noise interference, improve the signal-to-noise ratio of weak signals and ensure high accuracy of time difference measurement.

[0027] The working principle of this utility model is as follows: Installation and initialization stage: First, fix the meter body 1 horizontally to the gas pipeline, connect the gas inlet 2 to the gas source, and connect the gas outlet 3 to the user end, ensuring that the reduced diameter section 301 faces downstream. Then, power on for self-test. At this time, after the main control circuit board 7 is powered on, it automatically detects the signal strength of the ultrasonic transducer 401 and the reading of the temperature sensor 402. If the fluctuation is <±1%, it enters the standby mode. During the metering operation phase: First, the gas flows through the honeycomb rectifier 501 and the perforated plate 502, and the flow field is homogenized. Then, the ultrasonic transducer 401 alternately emits ultrasonic waves, and the main control circuit board 7 records the time difference between forward and reverse flow propagation. Finally, the dual temperature sensors 402 upload data in real time and calculate the average temperature. At the same time, the main control circuit board 7 combines the time difference and calculates the instantaneous flow rate to accumulate the gas consumption. Calibration and maintenance phase: For the first calibration, a standard flow rate (0.1 m³ / h-10 m³ / h) needs to be introduced. If the comparison error is >0.5%, the sound path parameter will be automatically corrected. At the same time, regular maintenance is required. Every 2 years, check the blockage of the rectifier and current stabilization components (if the pressure difference is >50 Pa, it needs to be cleaned). If the drift of the 402 temperature sensor is >0.5℃, it should be replaced.

[0028] It should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of the technical solution of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A high-precision gas metering device, comprising a meter body (1), an inlet (2) and an outlet (3) installed at both ends of the meter body (1) and connected to each other, and a metering core and a main control circuit board (7) installed on the meter body (1), characterized in that: The metering core includes a pair of ultrasonic transducers (401) for measuring gas flow rate, a rectifier and flow stabilizer assembly, and a temperature sensing assembly. The rectifier and flow stabilizer assembly is installed in the metering channel between the air inlet (2) and the ultrasonic transducer (401). The rectifier and flow stabilizer assembly includes at least one layer of honeycomb rectifier (501) and one layer of perforated plate (502). The honeycomb rectifier (501) is located upstream, and the perforated plate (502) is located downstream. The temperature sensing assembly includes two temperature sensors (402), which are installed upstream and downstream of the rectifier and flow stabilizer assembly, respectively. The main control circuit board (7) is electrically connected to a pair of ultrasonic transducers (401) and two temperature sensors (402), and the main control circuit board (7) is configured to calculate the gas flow rate based on the signal of the ultrasonic transducers (401) and the average temperature value of the two temperature sensors (402).

2. The high-precision gas metering device according to claim 1, characterized in that: The body (1) has an inwardly protruding reinforcing wall (6) at the mounting position corresponding to the ultrasonic transducer (401).

3. The high-precision gas metering device according to claim 1, characterized in that: The outlet (3) is provided with a venturi-structured narrowing section (301), and a widening section (302) is connected downstream of the narrowing section (301).

4. The high-precision gas metering device according to claim 1, characterized in that: The pair of ultrasonic transducers (401) are installed at an angle relative to each other, such that the ultrasonic signal propagation path forms an acute angle with the gas flow direction.

5. The high-precision gas metering device according to claim 1, characterized in that: The ratio of the honeycomb aperture of the honeycomb rectifier (501) to the aperture of the porous plate (502) is 2:1 to 5:1, and the porosity of the porous plate (502) is 40% to 60%.

6. The high-precision gas metering device according to claim 1, characterized in that: The two temperature sensors (402) are respectively embedded in the inner wall of the body (1), and the sensing end of the temperature sensor (402) is exposed in the metering channel.

7. The high-precision gas metering device according to claim 1, characterized in that: The main control circuit board (7) integrates a signal conditioning module (701) for amplifying, filtering and digitally processing ultrasonic signals.

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